1. Field of the Invention
The present invention relates to thermal transfer systems, and more particularly, to thermoelectric array configurations in which counterflows of a thermal transfer fluid are employed in a closed-cycle thermal transfer system.
2. Description of the Related Art
Electronic devices such as central processing units, graphic-processing units and laser diodes can generate substantial heat during operation. If such heat is not dissipated properly, temperature buildup may occur and such buildup can adversely affect the performance of these devices. For example, excessive temperature buildup may lead to malfunctioning or breakdown of the devices. Alternatively, stability or performance characteristics may be adversely affected. Accordingly, it is important to remove the generated heat in order to maintain desired operating temperatures of these devices.
In many challenging scientific and commercial cooling applications, particularly microelectronics, cooling of high power dissipation densities (e.g., densities >100 W/cm2) may be required. Worse still, these densities are projected to increase in the future. In general, such applications require cooling beyond what can be offered by conventional finned heat sink structures and forced air cooling. Consequently, alternatives such as single- and two-phase fluid cooling systems are being implemented more widely.
Characteristics such as low vapor pressure and high thermal conductivity make liquid metals attractive for high temperature cooling applications. Commonly-owned U.S. Pat. No. 6,658,861, entitled “Cooling of High Power Density Devices by Electrically Conducting Fluids” describes various exemplary liquid metal cooling configurations. In certain configurations, heat is transferred from a high power density device to the liquid metal, the liquid metal is transported away from the high power density device and heat is distributed and/or dissipated at a convenient distance (e.g., using a heat sink).
In addition to providing excellent heat transfer characteristics, the high electrical conductivity typical in this class of fluids offers the potential of efficient, compact pumping. Accordingly, liquid metals offer an attractive solution for current and future high power density cooling challenges. However, even with all the advantages of efficient forced flow liquid metal cooling, some cooling applications may require greater cooling power than can be achieved simply through simple rejection of heat from the liquid metal to an ambient environment. While ever larger heat sinks and forced air techniques can be employed to improve dissipation to the ambient environment, form factor or other constraints may limit these solutions. For these and other applications, improved techniques are desired.